1. Field of the invention
This invention relates to auto-loading of magnetic or optical tape cartridges or cassettes.
2. Description of the Prior Art
Cartridges such as 3480 style half-inch cartridges were originally designed to be used in manual load decks. These manual load decks have an enclosed supply hub for driving the tape reel, and a slot in the side of the deck through which the cartridge may be inserted. The manual loading operation is shown in FIGS. 1a, 1b and 1c of the accompanying drawings. Referring to FIG. 1a, the cartridge 1 is gripped, between the thumb on top of the cartridge and the index and second fingers underneath the cartridge, and the cartridge is pushed part-way into the slot 2 in the side of the manual load deck 3. The cartridge 1 is then either manually pushed further into the deck 3 into a position over the supply hub 4 as shown in FIG. 1b, or the cartridge 1 is gripped by a powered device 5 in the deck 3 and pulled into position over the supply hub 4 as shown in FIG. 1c. In the system of FIG. 1b, once the cartridge 1 is positioned over the supply hub 4, a spring-loaded device (not shown) is triggered to lower the cartridge down onto the teeth of the supply hub 4. In the system of FIG. 1c, the powered device 5 drives the cartridge down to engage with the supply hub 4.
As manual load decks became established, auto-loaders were designed to load cartridges automatically into the decks. Such auto-loaders are mechanical substitute hands designed to perform the complete sequence of loading operations originally done manually. FIGS. 2a and 2b of the accompanying drawings show the operation of such an auto-loader.
FIG. 2a shows a mechanical hand 10 transporting a cartridge 1 From a magazine of rack 11 to a deck 3, illustrating three successive stages of this operation. The cartridges 1 ape stacked vertically in the rack 11 with sufficient space between each cartridge to allow insertion of the mechanical hand 10 to grip a cartridge as shown in the Figure. Once the hand 10 has gripped the cartridge 1, the First stage of the operation is movement of the hand 10 in the direction of the arrow A in FIG. 2a to remove the cartridge from the pack 11. The next stage in the operation is rotation of the hand 10 through 180.degree. as shown by the arrows B in the figure. The hand 10 is then lowered to the level of the slot 2 and moved in the direction of the arrow C to insert the cartridge 1 partially into the slot 2 of the deck 3. If the deck mechanism is of the type shown in FIG. 1c, the powered device 5 then takes over to draw the cassette 1 into the slot and drive the cassette down onto the supply hub. If the deck system is of the type shown in FIG. 1b, the hand 10 must release the cartridge after it has been partially inserted into the slot 2, pull back away from the cartridge, close on itself and then continue to push the cartridge into the slot 2 as shown in FIG. 2b whereupon the spring-loaded device lowers the cartridge onto the teeth of the supply hub 4.
There are a number of disadvantages associated with existing auto-loader systems such as that previously described. For example, there is inefficient use of potential storage space in the rack due to the need to space the cartridges vertically sufficiently to enable access by the mechanical hand to grip a cartridge. There must also be sufficient space for the auto-loader to perform all the various separate manoeuvres of the loading procedure. In addition to inefficient use of space, the multiple operations involved in the loading process increase the complexity of the apparatus and the time taken to carry out the process.
FIG. 3 of the accompanying drawings shows schematically the successive stages of movement of a cartridge 1 during a typical multi-stage loading operation performed by known auto-loader apparatus, the apparatus being omitted for clarity. The cartridge 1 is first moved out of the rack (not shown) by horizontal movement as indicated by the arrow A. The cartridge is next moved vertically downwards, as indicated by the arrow B, until level with the slot 2 of the deck 3. The cartridge 1 is then partially inserted into the deck 3 as shown by the arrow C. The cartridge is then pushed fully into the deck 3, or is drawn in by a powered device in the deck, as shown by the arrow D. Finally, the cartridge is lowered vertically into engagement with the supply hub of the deck as shown by the arrow E. Depending on the way in which the cartridge 1 is grasped by the auto-loader apparatus, and the orientation of the cartridge in the rack, rotation of the cartridge, for example through 180.degree. as shown in FIG. 2a, may also be required. Thus, it can be seen that known loading processes require at least five stages of horizontal and vertical movement to perform the task of loading the cartridge 1 into the deck 3.